Fly Food
Ever had a summer picnic and spent most of your time trying to keep the wasps away? In this experiment you’re inviting the insects to eat your food. (Act like an amateur entomologist – that’s someone who studies insects – and see if the insect behaviour matches your predictions.)
You will need:
- Jam
- Ham slices (or something else if you are vegan or vegetarian)
- Bread
- Newspaper
- A garden table or something else above the ground
- Watch or stopwatch (optional)
- Pen and paper to make notes with (unless you think you have such a wonderful memory you don’t need to write anything down)
What to do:
- Make two sandwiches – one with jam and one with ham. Don’t add any extra bits like pickle or mustard. The insects won’t mind if you’re not a Cordon Bleu chef.
- Put your newspaper down on the table and your sandwiches on top of the paper, side by side.
- Record the date, the time you put down the sandwiches, the weather conditions and anything else you think might be important.
- Sit near the sandwiches and make your predictions about what will happen. What kind of insects will be attracted to the sandwiches? Which sandwich do you think they will prefer, and why?
- Watch the insects discover the gorgeous grub you have prepared for them. Use your paper to record your observations. How long does it take the insects to find your sandwiches? How do you think they found it? What do they do at the sandwich – feed, mate, lay eggs?
- All this hard observation work may make you feel a little peckish, but do not eat the sandwiches! When you have finished, fold the paper around the sandwiches without touching them with your hands, and throw them in the bin. Go inside and wash your hands with soap.
What’s going on?
Did you see any insects eating the ham sandwich? The insects will have been far more attracted to the sugary jam, and some may have spent quite a while exploring the sandwich and eating the jam. One of the ways that entomologists classify insects (into different groups and species) is by the kind of mouth they have and the way they eat. Some insects cut off their food and chew it with their mandibles in a very similar way to humans biting and chewing food with their teeth. Many wasps are predators and so they have mandibles to chew up their insect prey.
Other insects, like butterflies, can only eat liquid food and they suck it up through a long tube called a proboscis. When they aren’t using the proboscis they coil it underneath their head.
Non-biting flies (like house flies) sponge up their food. The proboscis of these insects has a spongy bit at the end on it. They can also only eat liquids, but they have a clever way of making solid food into a liquid they can then sponge up. They vomit saliva on the solid and then sponge up the saliva with the food dissolved in it.
Insects like honey bees have a combination of chewing and drinking mouths, known as chewing-lapping mouths. They can suck nectar from flowers and also chew up wax when they are making their hives.
The insects you saw would have depended on the season and the weather.
If you found this experiment interesting, the Amateur Entomology Society has a Bug Club for young amateur entomologists. You can also find lots more information about entomology on the Natural History Museum website.
This experiment came from Planet Science’s Little Book of Experiments.
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